In the third instance of a major grid collapse within a month's time, western Maharashtra, Marathwada and several parts of Mumbai were affected by a major power breakdown on Saturday afternoon.

The power failure occurred at around 1230 IST due to low voltage in the 400 kv Dhule-Itarsi transmission line, which led to a cascading effect, an MSEB official said.

Power supply in the Vidarbha region was partially affected as only few generating sets at the power stations, including Chandrapur and Koradi, were affected, he said, adding that it could be several hours before the power supply is fully restored.

Power supply in some areas in Mumbai seviced by the Reliance-run BSES was also affected.

However, large parts the city remained unaffected as the Tata Power Company landed itself at around 1238 hours, minutes after the grid collapse.

A senior MSEB official blamed a neighbouring state for the grid collapse. "Overdrawing of power by a neighbouring state and low voltage led to power disruption," he said.

On November 5 and 7 overdrawing of power had led to a blackout in some parts of Maharashtra and Gujarat.